Method of making cyanids.



No. 698,463. Patented Apr. 29, I902.

N J. D. DARLING.

METHOD, OF MAKING cvAmns.

(Application filed July 29, 1901.)

(No Model.)

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UNITED STATES A PATENT OFFICE.

JAMES D. DARLING, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO A HARRISONBROS. & (30., INCORPORATED, OF PHILADELPHIA, PENN- SYLVANIA, ACORPORATION OF PENNSYLVANIA.

METHOD OF MAKING CYAN IDS.

srEoIFIoATIoN forming part of Letters Patent No. 698,463, dated April29, 1902.

Application filed July 29,1901. Serial No. 70,024. ar ament.)

To alt whom it may concern.-

Be it known that I, J AMES D. DARLING, a citizen of the United States,residing at No. 4826 Greenway avenue, in the city and county ofPhiladelphia and State of Pennsylvania, have invented a certain new anduseful Improvement in the Manufacture of Alkaline Oyanids, of which thefollowing is a specification, reference being bad to the accompanyingdrawing.

There are many well-known processes by which the formation of alkalinecyanid is accomplished by the direct combination at proper temperaturesof carbon, alkali, and nitrogen. In most of these processes the alkaliis supplied in theform ofa hydrate or carbonate. In this case it isnecessary to supply more carbon than is theoretically required, and as aresult the product is a black mass consisting of alkaline cyanid with acon-' siderable excess of carbon, sometimes termed cyanized carbon. Itis necessary in order to produce a marketable article to remove thecarbon, which has usually been accomplished either by converting thecyanizedcarbon into ferrocyanid or by filtration processes, which aretedious and expensive. In certain other processes the alkali issuppliedin metallic form. In this case it is possible to convert all ofthe carbon into alkaline cyanid; but the process is attended by thedisadvantage of the comparatively high cost of the alkali metal;Furthermore, the nitrogen must then besupplied in the form of ammonia,which is much more expensive than nitrogen by itself.

By my present invention I employ as the chief source of alkali thecheaper carbonate, hydroxid, or oxid,(preferably the latter,) and I getrid of the excess of carbon which would remain if nothing else were usedby subjecting the cyaniz'ed carbon thus produced to the action of alkalimetal and ammoniagas, whereby an additional quantity of alkaline cyanidis formed by the combination of this excess of carbon with the alkalimetal and ammonia-gas.-

For carrying out my process no particular form of apparatus isnecessary; but I prefer to employ one such as I have figured in theaccompanying drawing, in which A is a furnace having set within it largeclosed iron vessels B B. Two only are shown;

but it is understood that any desired number may be employed. Each ofthese vessels contains an inlet-pipe O, reaching nearly to the bottom,and an outlet-pipe D, leading from the top. The vessels are connected inseries, as shown.

In my present process I introduce into each of the vessels an alkalinecarbonate, hyd roxid', or oxid, and also carbon, which, as aboveexplained, must be in excess. I also place in the bottom of the vessel aquantity of alkali metal which, in conjunction with the necessary amountof nitrogen, will be suflicient to combine with the excess of carbon andproduce a quantity of cyanid additional to that produced from thefirst-mentioned alkaline element. As soon as these materials have beenbrought to the proper temperature I pass into the vessel at G a mixtureof ammonia-gas and pure nitrogen, whereby two processes go onsimultaneously. The nitro gen gas passes through the alkali metal without action and upon reaching the heated carbon and alkaline carbonate,hydroxid, or oxid it combines therewith to form a cyanid. On the otherhand, the ammonia-gas combines with the alkali metal and the remainderof the carbon, forming an additional quantity of cyanid, the proportionsof the ingredients being so supplied that as a result there remains inthe vessel nothing but a mass of pure cyanid.

As an example of the proper proportions to employ in this process I maytake eighty pounds of caustic soda, twenty-three pounds of sodium, andsixty pounds of charcoal. Through these must be passed not less thantwenty-eight pounds of nitrogen and seventeen pounds of ammonia-gas. Asa result of the passage of the twenty-eight pounds of nitrogen throughthe caustic and charcoal there will be produced ninety=eight pounds ofalkaline cyanid, leaving twelve pounds of carbon in excess, and as aresult of the-combination of this excess of carbon with the sodium andthe nitrogen of the ammonia-gas there will be formed forty-nine poundsmore of the alkaline cyanid, so that the result of the entire processwill be one hundred and forty-seven pounds of pure alkaline cyanid.

I have spoken of the ammonia and alkali metal as combining directly withthe carbon. It seems probable that there is formed intermediately analkaline amid, which in turn combines with the carbon'to form thecyanid.

Consequently my process includes the use of an alkaline amid previouslyformed in place I speak of supplying nitrogen such supply may be eitherin the pure form or combined with other substances, and I desire it alsoto be understood that where in the claim I speak of an alkaline oxid Imean to include in said term alkaline hydroxids and carbonates, whichare the equivalent thereof.

Having thus described my invention, I claim The process of producingpure alkaline cyanid, which consists in subjecting carbon and alkalineoxid to the action of nitrogen and simultaneously subjecting the excessof carbon to the action of alkali metal and ammonia, all under theinfluence of heat, substantially as described.

JAMES D. DARLING.

Witnesses:

JAMES H. BELL, JOSEPH L. LUPTON.

